Deaeration installation for a boiler



March 23, 1 3 YOSHITERU lWAMOTO 3,174,465

DEAERATION INSTALLATION FOR A BOILER Filed Oct. 15, 1962 INVENTOR. YOS HITER U IWAMOTO ATTOR NEY United States Patent Ofi ice 3,174,465] Patented Mar. 23,1965

3,174,465 DEAERATION INSTALLATION FOR A BOILER Yoshiteru Iwarnoto, Takatsuhi, Osaka Prefecture, Japan, "assignor to Takurna Boiler Manufacturing (10., Kitaltu,

Osaka, Japan, a corporation of Japan Filed Oct. 15, 1962, Ser. No. 230,348 3 Claims. (Cl. 122-459) This invention relates to a deaeration installation for a boiler, especially a forced circulation boiler wherein heating tubes which generate steam for deaeration are installed in the flue of'the boiler.

An object of my invention is to provide a forced circulation boiler with a new and effective deaeration equipment or installation which includes heating tubes installed in the flue of the boiler. Previous types of pressurized deaerators are operated by steam which is generated in the main heating tubes of the boiler and from the main heat source of the boiler itself. With the structure previously used no improvement of boiler efiiciency can be obtained since the boiler is required to generate additional steam for the deaerators. Therefore, in structures previously in use, and in the case of forced circulation boilers, the pump loss is increased; also an automatic temperature regulator is required.

Another object of my invention, therefore, is to provide deaeration equipment in a boiler in which the pump loss is not increased, and also where an automatic regulator is not required.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

FIGURE 1 is a vertical sectional view of a forced circulation boiler including my invention.

FIGURE 2 is a diagrammatic view of a forced circulation boiler including my invention.

Referring more particularly to the drawing, the main principle of this invention is to lead extra feedwater from the feedwater chamber inside the steam separator into the heating tubes installed in the fine of the boiler. The feedwater has been already deaerated by the deaerator structure and passes through the constant water level controlling device, consisting of a steam trap and other structures, and then to lead the steam water mixture into the deaerator after steam has been generated in the heating tubes in the fine for the purpose of using the steam water mixture as the heating source for the deaerator. The forced circulation boiler 1 includes the usual water tubes 2 which are heated from a suitable source of heat 3, all of which is usual and well known in the art. The boiler 1 includes the usual fine or gas outlet chimney 4 through which the eated combustion gases flow.

A deaerator feedwater pump 5 forces water into the heat exchanger 6. A deaerator tank or cylinder 7 receives water from the heat exchanger 6 through the pipe 8. The incoming feedwater can also be passed through the heat exchanger coil 9 by manipulation of the by-pass valve 10. The water level in the deaerator chamber 7 is controlled by the float valve 11 through the float 12 within the deaerator chamber. The pump 5 forces the feedwater into the top of the deaerator 7 through the pipe 8. The return pipe 13 extends from the deaerator heating tubes 14 into the top of the deaerator 7. The feedwater passes in through the pipe 15 into the deaerator heating tubes 14 from the steam separator 16. The pipe 15 extends through a control level chamber 17 and thence into an annular chamber 18 within the steam separator 16. Water is forced through the evaporating tubes 2 by the pump 19 in the pipe 20 which carries water from the steam separator 16 and thence into the evaporating tubes. The annular chamber 18 is supplied with water by the pump 21 in the pipe 22, Which pipe extends from the deaerator 7 and thence into the annular chamber 18 in the steam separator 16.

A separation wall 23 in the annular chamber 18 is provided with an outlet hole 24 which permits water to flow from the annular chamber 18 and thence into the main chamber of the steam separator 16. Thus there will be a mixing of the main feedwater, and also the dcaerated water from the coils 14. A steam discharge pipe 25 extends from the top of the steam separator 16. A blowdown pipe 26 extends from the inside of the stem separator 16 and below its normal water level, and thence through the coil 27 in the heat exchanger 6. A valve 28 controls the flow of water through the pipe 26. The blow-down through the pipe 26 is continuous in my boiler construction.

The operation of my forced circulation boiler 1 provides means to direct the extra feedwater in the feedwater chamber 18 in the steam separator 16. This is accomplished through the constant water level controlling device 17, which may be a steam trap or a similar structure. The feedwater is then fed to the deareator tubes 14 which are positioned in the flue or chimney 4 of the boiler, or in the direct flow of hot combustion gases from the burner 3. The hot gases, of course, heat the fiues 2 in the usual manner to generate steam in these tubes. The steam water mixture of approximately 10% to 20% dryness is sprayed from the tubes 14 into the upper portion of the deaerator cylinder '7 for the purpose of using this deaerator as a heat source to deaerator the steam water mixture.

Since the boiler 1 is provided with deaeration tubes 14, which are positioned in the flow of the exhaust gases, the elficiency of the boiler increases by as much as the heat recovered by the tubes 14, and the boiler itself is not required to generate additional steam for deaeration purposes. Consequently, circulation pump loss does not increase in my boiler, as in the case of other types of forced circulation boilers.

Furthermore, I have found that the heat recovered by the deaeration tubes 14 is almost proportional to the load of the boiler, namely, the amount of feedwater circulated through the boiler. Thus the amount of steam generated for the deaerator is almost balanced with that of the feedwater. As a result no automatic regulator is required. A further advantage of my boiler is that the feedwater flows into the heating tubes 14 after being deaerated; consequently, there is no fear of corrosion on the inside of these heating tubes.

Having described my invent-ion, I claim:

1. In a boiler including evaporaiton tubes therein; a heating means in the boiler and a flue through which the exhaust hot gases pass,

a feedwater deaeration means comprising deaeration tubes positioned in the boiler within the flow path of the hot gases in said boiler,-

a deaeration cylinder,

feedwater intake means extending into the deaeration cylinder,

one end of the deaeration tubes being piped to the deaeration cylinder,

a conduit means extending from the deaeration cylinder to said deaeration tubes,

a steam separator cylinder,

said conduit means extending into the steam separator,

a circulation pump arranged between and connected to,

said steam separator and the evaporation tubes,

said steam separator having a feedwater chamber therein, p v

said feedwater intake means extending into the fcedwater chamber,

said teedwater chamber having an outlet hole therein opening into the steam separator,

a blow-down pipe extending from said steam separator.

2. In a boiler including evaporation tubes therein; a heating means in the boiler and a flue through which the exhaust hot gases pass,

a feedwater deaeration means comprising deaeration tubes positioned in the boiler within the fiow path of the hot gases in said boiler,

a deaeration cylinder,

feedwater intake means extending into the deaeration cylinder,

one end of the deaeration tubes being piped to the deaeration cylinder,

a steam separator cylinder,

said steam separator cylinder having a feedwater chamber therein,

one end of the deaeration tubes being piped into the feedwater chamber,

a level control chamber arranged in the last named said feedwater chamber having a hole therein opening into the steam separator cylinder.

3. In a boiler including evaporation tubes therein; a heating means in the boiler and a fiue through which the exhaust hot gases pass,

a feedwater deaeration means comprising deaeration tubes positioned in the boiler within the flow path of the hot gases in said boiler,

a deaeration cylinder,

feedwater intake means extending into the deaeration cylinder,

one end of the deaeration tubes being piped to the deaeration cylinder,

a steam separator cylinder,

said steam separator cylinder having a feedwater chamber therein, one end of the deaeration tubes being piped into the 10 feedwater chamber,

a level control chamber arranged in the last named pipe, said feedwater chamber having a hole therein opening into the steam separator cylinder, and a blow-down pipe extending from said steam sep- 15 arator cylinder.

References Cited by the Examiner UNITED STATES PATENTS 1,039,586 9/12 Patten. 20 1,314,140 8/19 Jacobus.

2,636,485 8/53 Hillier 122-451 2,743,709 5/56 Armacost 122-411 2,879,750 3/59 Engel 122379 KENNETH W. SPRAGUE, Examiner. 

1. IN A BOILER INCLUDING EVAPORATION TUBES THEREIN; A HEATING MEANS IN THE BOILER AND A FLUE THROUGH WHICH THE EXHAUST HOT GASES PASS, A FEEDWATER DEAERTION MEANS COMPRISING DEAERATION TUBES POSITIONED IN THE BOILER WITHIN THE FLOW PATH OF THE HOT GASES IN SAID BOILER, A DEAERATION CYLINDER, FEEDWATER INTAKE MEANS EXTENDING INTO THE DEAERATION CYLINDER, ONE END OF THE DEAERATION TUBES BEING PIPED TO THE DEAERATION CYLINDER, A CONDUIT MEANS EXTENDING FROM THE DEAERATION CYLINDER TO SAID DEAERATION TUBES, A STEAM SEPARATOR CYLINDER, SAID CONDUIT MEANS EXTENDING INTO THE STEAM SEPARATOR, A CIRCULATION PUMP ARRANGED BETWEEN AND CONNECTED TO SAID STEAM SEPARATOR AND THE EVARPORATION TUBES, SAID STEAM SEPARATOR HAVING A FEEDWATER CHAMBER THEREIN, SAID FEEDWATER INTAKE MEANS EXTENDING INTO THE FEEDWATER CHAMBER, SAID FEEDWATER CHAMBER HAVING AN OUTLET HOLE THEREIN OPENING INTO THE STEAM SEPARATOR, A BLOW-DOWN PIPE EXTENDING FROM SAID STEAM SEPARATOR. 